Will,

I've never had a problem leaving my CatTrax ... I do put my sail number on them for identification purposes.

I think I'd prefer to CatTrax than the PVC sliders...since those will only be 2" diameter it still leaves room for the boat (while at an angle) to slide on the ramp and damage the gelcoat.

I'd recommend getting an 18" screw anchor (Ace Hardware around here have them ... longer ones at Lowes and Home Depot). Put on a diving mask and auger it offshore a bit ... tie a buoy (milk carton can work) ... and submerge it about a foot below the surface if you think someone might disturb it....then you can secure your boat off to this while you retrieve your wheels. I know the guys in Jacksonville even raise/lower their sails while moored depending on wind direction.